Although there is no single, specific test that can diagnosis multiple sclerosis with 100 percent accuracy, imaging and laboratory testing is very important to assist in the diagnostic process.
Your health care provider may suggest one or more of the following tests to help make a firm diagnosis:
Magnetic resonance imaging (MRI) is the major diagnostic laboratory tool that can support the diagnosis. Particular characteristics of imaging findings include multiplicity of lesions (changes in the brain), large diameter, and ovoid shape in particular locations in the brain typical of MS.
An MRI scanner exerts powerful magnetic fields and radio waves around a patient who lies in a tube. It produces very accurate images of the patient's internal organs—in this case, the brain and the spinal cord in particular. An MRI cross section of the brain and spinal cord can reveal formerly hidden MS lesions.
If the MRI findings are inconclusive, the person might have to undergo a lumbar puncture (spinal tap) to examine the cerebrospinal fluid (spinal fluid contents) to evaluate for immunologic patterns. Spinal fluid provides important complementary information to rule out other conditions related to infections or other diseases as well as to support the diagnosis of MS.
Blood tests, like spinal taps, are used to exclude other diagnoses.
Evoked Potential Tests
Evoked potential testing can be prescribed when the results continue to be inconclusive. These are tests consist of stimulation of the nerves in the visual pathway, brainstem tract, and spinal cord. When conduction of impulses occurs, these findings can verify the diagnosis of possible multiple sclerosis. These tests are usually painless and non-invasive and can assist the clinician when the final diagnosis is uncertain.
The diagnosis of MS is now facilitated by state-of-the-art laboratory testing but is still based on the clinical expertise of the MS clinician who considers the age, gender, history, and neurologic findings of each person who presents with problems.